Scrotal Mass: Causes and When to Worry

Feeling for the lump: where it is matters

The scrotum contains each testicle, the epididymis (a coiled tube behind and on top of the testicle that stores sperm), the spermatic cord (blood vessels and the vas deferens) and the covering layers. Doctors sort scrotal masses by whether they are inside or outside the testicle:

Painless scrotal masses

Epididymal cysts and spermatoceles

Smooth, round, fluid-filled lumps on the epididymis, usually at the top of the testicle. They are separate from the testicle and very common. They need treatment only if large or uncomfortable. See spermatocele.

Hydrocele

Fluid collects around the testicle, causing a smooth, painless swelling that may make the whole side look larger. Light shines through it (transillumination). Common in newborns, where it often resolves by age 1, and in older men. See hydrocele.

Varicocele

Enlarged veins above the testicle, usually on the left, feeling like a "bag of worms." They are more noticeable when standing and can cause a dull ache. They are linked to reduced fertility in some men. See varicocele.

Testicular cancer

Usually a firm, painless lump or hardness in the testicle, or a testicle that has become larger or heavier. Some men feel a dull ache in the lower belly or groin. It is most common between ages 15 and 35. Risk factors include an undescended testicle, a previous testicular cancer, a father or brother with it, and HIV. It is highly curable, with cure rates above 95%, especially when found early. See testicular cancer.

Painful scrotal masses

Scrotal mass between the testicles

A lump in the middle of the scrotum, between the testicles, is usually in the skin or the tissue under it rather than in a testicle. Causes include an epidermoid or sebaceous cyst (a small, firm, round skin lump), an ingrown hair, a pimple or boil, scrotal calcinosis (multiple hard white nodules), or rarely an abscess. A swelling that changes with coughing or standing may be a hernia. A doctor can usually tell from examination and an ultrasound if needed.

How doctors evaluate a scrotal mass

1. History: when you noticed it, pain, injury, urinary symptoms, sexual history, fever.
2. Examination: standing and lying, feeling each testicle, the epididymis and cord, checking whether the lump transilluminates and whether it changes with coughing.
3. Scrotal ultrasound with Doppler: the key test. It shows whether the mass is in the testicle, whether it is solid or fluid, and blood flow, which helps diagnose torsion and infection.
4. Urine tests and STI testing for suspected epididymitis.
5. Tumor markers (AFP, beta-hCG and LDH blood tests) if cancer is suspected, followed by CT scans for staging.

Suspected torsion goes straight to surgery without waiting for imaging if the story is typical.

Treatment

• Cysts, hydroceles and varicoceles: often no treatment. Surgery for large, painful or fertility-affecting cases.
• Epididymitis: antibiotics chosen by likely cause, plus rest, scrotal support, ice and pain relief. Partners are treated if an STI is the cause.
• Torsion: emergency surgery to untwist and fix both testicles.
• Testicular cancer: removal of the affected testicle through a groin incision (radical inguinal orchiectomy), sometimes followed by surveillance, chemotherapy or radiation. Sperm banking is offered beforehand.
• Hernia: surgical repair.

Checking your testicles

Many testicular cancers are found by men themselves. Once a month, after a warm shower, gently roll each testicle between your thumb and fingers. It is normal for one to be slightly larger and to feel the soft epididymis at the back. Report any new lump, hardness, change in size or heaviness.

Frequently asked questions

What causes a scrotal mass?

Most scrotal masses are harmless: epididymal cysts, spermatoceles, hydroceles, varicoceles and hernias. Painful masses are often due to infection (epididymitis) or torsion. A firm, painless lump inside the testicle can be testicular cancer, so every new lump should be examined and usually scanned.

Is a painful scrotal mass serious?

It can be. Sudden severe pain may be testicular torsion, which needs surgery within hours to save the testicle. Pain developing over a day or two is often epididymitis, which needs antibiotics. Testicular cancer is usually painless, but pain does not rule it out.

What is a lump between my testicles?

A small lump in the middle of the scrotum is usually in the skin, such as an epidermoid cyst, ingrown hair or boil, rather than in the testicles. These are generally harmless. Have it checked if it grows, becomes painful or red, or you are unsure.

Who is at risk of testicular cancer?

It mostly affects men aged 15 to 35. Risk is higher with an undescended testicle (even if corrected), a previous testicular cancer, a father or brother who had it, HIV, and in white men. It is rare overall and very treatable.

Can a scrotal mass go away on its own?

Some can. Infections improve with treatment, newborn hydroceles often disappear by age 1, and small cysts may shrink. Solid lumps in the testicle do not go away and need prompt assessment. Never wait to see if a hard testicular lump disappears.